Property, Plant and Equipment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Abstract]
Rental expense	$ 6,416	$ 6,221	$ 5,830
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	278,628	264,960
Less: Accumulated depreciation	(139,587)	(125,773)
Total property, plant and equipment	139,041	139,187
Future minimum lease commitments for operating leases
2013	7,128
2014	5,787
2015	5,001
2016	3,531
2017	3,275
Thereafter	8,027
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,243	4,367
Building and improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	92,775	90,360
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	176,102	163,923
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 5,508	$ 6,310